Sand Worm, Adult (CR 4)
This large desert worm is covered with sand-colored plates of chitinous armor. Its trifurcated mouth opens to reveal row upon row of razor sharp teeth.
XP 1,200
N Huge magical beast (desert, earth)
Init +0; Senses darkvision 60 ft., low-light visions, tremorsense 60 ft.; Perception +7
DEFENSE
AC 21, touch 8, flat-footed 21 (–2 size, +11 natural armor)
hp 49 (5d10+27)
Fort +8, Ref +4, Will +2
Immune acid, fire, paralysis, and poison
Weaknesses susceptible to cold
OFFENSE
Speed 30 ft., burrow 30 ft.
Melee bite +11 (2d6+7/19-20 plus grab)
Space 15 ft., Reach 10 ft.
Special Attacks sand tremor, swallow whole (3d6 acid damage, AC 16, 20 hp)
TACTICS
The favored tactic of the sandworm is to lurk beneath the surface of the desert sands until it senses a creature moving by with its tremorsense, whereupon it burrows out to surprise and attack its prey (treat this attack as a charge attack). A sandworm that has taken more than half its hit points in damage retreats deep into the sands unless it is cornered, in which case it fights to the death.
STATISTICS
Str 24, Dex 11, Con 18, Int 3, Wis 12, Cha 5
Base Atk +3; CMB +12; CMD +22 (can't be tripped)
Feats Skill Focus (Perception), Toughness, Weapon Focus (bite)
Skills Perception +11
Language Terran (can’t speak)
SPECIAL ABILITIES
Sand Tremor (Ex)
When an adult sandworm burrows within 15 feet of a creature, it creates a minor earthquake that can trip creatures. The sandworm attempts a single combat maneuver check and applies the result against the CMD of every creature in the area. If its roll equals or exceeds a creature's CMD, that creature is knocked prone. This trip attack does not provoke an attack of opportunity, nor is the sandworm knocked prone if it fails the check by 10 or more. Unlike with a regular trip attack, the sandworm can trip any creature touching the ground, regardless of size. Improved Trip does not affect this ability in any way. Though the earthquake is small and focused on the ground, if the area is particularly unstable, the tremor might cause items to topple, stones to shake loose from the walls or ceiling, and so on at the GM's discretion.
ECOLOGY
Environment warm deserts (underground)
Organization solitary, pair, cluster (2-5), or brood (3–6)
Treasure incidental